Model Diagnostic Discussion NWS Weather Prediction Center College Park MD 1145 PM EST Thu Feb 21 2019 Valid Feb 22/0000 UTC thru Feb 25/1200 UTC ...See NOUS42 KWNO (ADMNFD) for the status of the upper air ingest... 00Z Model Evaluation...with Preferences and Confidence ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ...Closed low ejecting out of the Southwest... ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Preference: Non-NCEP consensus led by the 12Z ECMWF Confidence: Slightly above average Regarding the closed low crossing the Southwest, this energy will eject out across the southern Plains and then northeast up across the Midwest and Great Lakes Saturday and Sunday while gradually phasing with digging northern stream energy over the northern Plains. By Sunday night and through early Monday, the phased system will advance east across portions of southern Ontario/southern Quebec and the interior of the Northeast which will foster secondary cyclogenesis near coastal areas of northern New England. The 00Z GFS as was the case over the last few model cycles tracks its surface and mid level low centers a tad north and west of the model consensus. It should be noted that the 18Z GEFS mean and 00Z GFS are also more out of tolerance with the other models across the central Plains with the placement of a front which it has positioned farther back to the north and west. The 12Z UKMET also is similar to the GFS with its low track at least until about 60 hours, and then begins to come into better agreement with the 12Z CMC/ECMWF which are a little farther south, and gradually a bit slower than the GFS. The UKMET/CMC/ECMWF camp all show reasonably good agreement with the secondary cyclogenesis impacting New England too, and tend to be again a little slower than the GFS. The 12Z ECENS mean is also supportive of the ECMWF-led non-NCEP consensus. The 00Z NAM for its part is south of the GFS track over the central Plains and Midwest, but gradually the NAM outruns the entire model suite after 48 hours as it approaches and then crosses the Great Lakes and Northeast. The ECMWF is reflecting good run to run continuity with this system, and has a bit broader deterministic and ensemble support, and thus the preference will be a non-NCEP consensus led by the 12Z ECMWF. ...Pacific Northwest trough/closed low Sat/Sun... ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Preference: General model blend Confidence: Above average Across the Pacific Northwest by early Sunday, there will be another shortwave trough and possible closed low arriving for which the guidance is in rather good agreement mass field wise. A general model blend can be preferred for now with this system. Model trends at www.wpc.ncep.noaa.gov/html/model2.shtml 500 mb forecasts at www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml Orrison